"Just had a very open and successful presidential election," Trump tweeted Thursday around 9 a.m., as scores of furious New Yorkers rallied outside of Manhattan's Trump Tower. "Now professional protesters, incited by the media, are protesting. Very unfair!"

Donald Trump tweeted support of the protests early Friday, just after complaining about them. (Donald Trump via Twitter)

Anti-Trump protests cropped up across the country Thursday for a second night in a row.

In San Francisco's downtown, high-spirited high school students marched through, chanting "not my president" and holding signs urging a Donald Trump eviction.

Protesters in Denver, Minneapolis and Los Angeles were able to briefly shut down highways as they marched through the streets.

Trump's early morning supportive tweet is not the first time he empathized with activists angry over a presidential outcome. After President Obama was reelected in 2012, beating Republican Mitt Romney, Trump encouraged angry voters to demonstrate.

"We can't let this happen," he tweeted in November 2012. "We should march on Washington and stop this travesty. Our nation is totally divided!"